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| PERFORMANCEPROBLEMS |
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| CHART |
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What to Do When |
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| PROBLEM |
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| PROBABLE | CAUSE |
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| CORRECTION |
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| Incorrect |
| size needle. |
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| Choose | correct size needle for thread and fabnc. |
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Skipping | Stitches |
| Bent or blunt needle. |
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| Insert new | needle. |
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| Incorrect |
| needle | instaiation. |
| Reinstall | needle. |
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| Tight upper thread | tension, |
| Loosen | upper | thread tension. |
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| Starting | to stitch | too last. |
| Start to stitch | at a medium |
| speed, |
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| improper threading. |
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| Rethread | machine. |
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| Tight upper thread | tension. |
| Loosen | upper | thread tension. |
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Breaking | Upper | Thread | incorrect | size needJe. |
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| Choose | correct | size needle | for thread | and fabnc. |
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| Sharp |
| eye in needle, |
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| insert new | needle. |
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| Nicks | or burrs | on shuttle. |
| Replace | shuttle, | or polish | off burn completely. |
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| Nicks | or burrs | at hole | st needle | plate. | Replace needle plate, or polish off burrs completely. |
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Breaking | Bobbin | Thread | Improper |
| bobbin | case | threading. |
| Check | bobbin | case | threading. |
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| Lint in bobbin | case | or shuttle. |
| Clean | bobbin | case | and | shuttle. |
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| Darning | plate | in place. |
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| Remove | darning | plate. |
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Fabric not Moving | Stitch |
| Length | set | at "'O". |
| Adjust | Stitch | Length | Control. |
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| Thread | knotted under | tabric. |
| Place both threads back under presser | toot betore | beginning | to stitch, | ||||||||||||||||
Machine | Jamming; Knocking Noise | Thread | caught | in shuttle. |
| Disassemble | and clean | shuttle. |
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| Lint in bobbin | case | or shuttle. |
| Clean bobbin case and shuttle. |
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| Incorrect |
| size | needle. |
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| Use correct size | needle | tot thread and | fabric. |
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| tmproper threading. |
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| Rethread | machine. |
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lrreguIar | Stitches |
| Loose |
| upper thread | tension. |
| Tighten | upper thread tension. |
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| Pulling |
| tabne. |
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| Do not pull fabnc; guide | it gently. |
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| Loose |
| presser | foot. |
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| Reset | presser toot. |
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| Unevenly | wound | bobbin. |
| Rewind | bobbin. |
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| Nicks | or | burrs | at | hole | st needle | plate. | Replace | needle | plate, or polish off burrs completely. |
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| Pulling |
| tabnc. |
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| Do not pull fabric; guide | it gently. |
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Breaking | Needle |
| Incorrect |
| size | needle. |
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| Choose | correct | size needle | for thread | and fabne. |
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| Incorrect needle | instalation. |
| Reinstall | needle. |
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| Loose |
| presser | toot. |
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| Tighten | presser | toot, |
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| Upper |
| and lower | threads not drawn back | When | starting | a seam be sure to draw | both threads under | and | |||||||||||||||
Thread | Bunching |
| under |
| presser foot betore starting seam. | back | st presser | foot | about |
| 4" and hold | until a few | stitches | are | formed. | |||||||||||
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| incorrect thread tension (s). |
| Reset | thread | tension(s). |
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| Using |
| two | different | sizes or kinds of thread. | Upper | thread | and bobbin | thread should be same | s_ze and | kind. | |||||||||||||
Puckenng |
| Bent or | blunt | needle. |
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| Insert | new needle. |
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| Loose |
| presser foot. |
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| Tighten | presser | toot. |
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| Fabric very sheer or very soft. |
| Use underlay | of tissue | paper. |
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